Supergranulation and poleward migration of the magnetic field at high latitudes of the Sun
L. P. Chitta, D. Calchetti, J. Hirzberger, G. Valori, E. R. Priest, S. K. Solanki, D. Berghmans, C. Verbeeck, E. Kraaikamp, K. Albert, T. Appourchaux, F. J. Bailén, L. R. Bellot Rubio, J. Blanco Rodríguez, A. Feller, A. Gandorfer, L. Gizon, A. Lagg, A. Moreno Vacas, D. Orozco Suárez, J. Schou, U. Schühle, J. Sinjan, H. Strecker, R. Volkmer, J. Woch, X. Li, T. Oba, A. Ulyanov
公開日: 2025/9/30
Abstract
Magnetoconvection at the solar surface governs the dynamics in the upper solar atmosphere and sustains the heliosphere. Properties of this fundamental process are poorly described near the solar poles. Here we report the first out-of-ecliptic remote-sensing observations of the south pole of the Sun from a high-latitude campaign of the Solar Orbiter spacecraft which reveal spatial and temporal evolution of supergranular convective cells. The supergranular cells have spatial scales of 20--40\,Mm. From eight days of observations starting on 2025 March 16, our analysis shows that the magnetic network migrates poleward, on average, at high latitudes (above 60\textdegree), with speeds in the range of 10--20\,m\,s$^{-1}$, depending on the structures being tracked. These results shed light on the buildup of the polar magnetic field that is central to our understanding of the solar cycle and the heliospheric magnetic field.